Sync with upstream repo

1. Magento Architecture and Customization Techniques/3. Utilize configuration XML and variables scope.md

@@ -6,15 +6,15 @@
 - `address_formats.xml`
 - `address_types.xml` - format code and title only
 - `cache.xml` - name, instance - e.g. full_page=Page Cache
-- `catalog_attributes.xml` - catalog_category, catalog_product, unassignable, used_in_autogeneration, quote_item
+- `catalog_attributes.xml` - catalog_category, catalog_product, unassignable, used_in_autogeneration, quote_item [*](https://www.atwix.com/magento-2/how-to-access-custom-catalog-attributes/)
 - `communication.xml`
 - `config.xml` - defaults
-- `crontab.xml` - group[], job instance, method, schedule
-- `cron_groups.xml`
-- `di.xml` - preference, plugins, virtual type
+- `crontab.xml` - group[], job instance, method, schedule [*](https://github.com/magento-notes/magento2-exam-notes/blob/master/1.%20Magento%20Architecture%20and%20Customization%20Techniques/6.%20Configure%20event%20observers%20and%20scheduled%20jobs.md#crontabxml)
+- `cron_groups.xml` [*](https://github.com/magento-notes/magento2-exam-notes/blob/master/1.%20Magento%20Architecture%20and%20Customization%20Techniques/6.%20Configure%20event%20observers%20and%20scheduled%20jobs.md#cron-groups)
+- `di.xml` - preference, plugins, virtual type [*](https://devdocs.magento.com/guides/v2.2/extension-dev-guide/build/di-xml-file.html)
 - `eav_attributes.xml` - locked entity attributes (global, unique etc.)
 - `email_templates.xml` - id label file type module -- view/frontend/email/name.html
-- `events.xml` - observers, shared, disabled
+- `events.xml` - observers, shared, disabled [*](https://github.com/magento-notes/magento2-exam-notes/blob/master/1.%20Magento%20Architecture%20and%20Customization%20Techniques/6.%20Configure%20event%20observers%20and%20scheduled%20jobs.md#demonstrate-how-to-configure-observers)
 - `export.xml`
 - `extension_attributes.xml` - for, attribute code, attribute type
 - `fieldset.xml`

1. Magento Architecture and Customization Techniques/7. Utilize the CLI.md

@@ -48,21 +48,32 @@ This class must extends from [\Symfony\Component\Console\Command\Command](https:
 <?php
 namespace Vendor\Module\Console\Command;
 
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputOption;
+
 class ExampleCommand extends \Symfony\Component\Console\Command\Command
 {
     protected function configure()
     {
-        $options = [
-            new \Symfony\Component\Console\Input\InputOption(
-                'param',
-                null,
-                \Symfony\Component\Console\Input\InputOption::VALUE_REQUIRED,
-                'Param description'
-            ),
-        ];
         $this->setName('example:hello')
-            ->setDescription('Hello world command')
-            ->setDefinition($options);
+            ->setDescription('Hello world command');
+
+        // Positional argument
+        $this->addArgument(
+            'myargument',
+            InputArgument::REQUIRED,
+            'Positional required argument example'
+        );
+
+        // Not required option
+        $this->addOption(
+            'myoption',
+            null,
+            InputOption::VALUE_OPTIONAL,
+            'Option example',
+            ScopeConfigInterface::SCOPE_TYPE_DEFAULT
+        );
+
         parent::configure();
     }
 

1. Magento Architecture and Customization Techniques/Magento Architecture and Customization Techniques.md

@@ -329,7 +329,7 @@ generate
 check for standalone process
 ```
 
-\Magento\Cron\Model\Config\Data extends \Magento\Cron\Model\Config\Data
+`\Magento\Cron\Model\Config\Data` extends `\Magento\Framework\Config\Data`
 - merges \Magento\Cron\Model\Config\Reader\Db::get from Database
 
   Sample DB structure:

2. Request Flow Processing/1. Utilize modes and application initialization.md

@@ -9,11 +9,11 @@
 
 - configure autoloader - PSR-4 prepend generation\Magento
 
-\Magento\Framework\App\Bootstrap::*createApplication*
+[\Magento\Framework\App\Bootstrap](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/App/Bootstrap.php)::*createApplication*
 
 - just call object manager->create
 
-\Magento\Framework\App\Bootstrap::*run*
+[\Magento\Framework\App\Bootstrap](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/App/Bootstrap.php)::*run*
 
 - set error handler
 - assert maintenance
@@ -27,7 +27,7 @@
 
 ### Application class
 
-bootstrap->createApplication() 
+[bootstrap->createApplication()](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/App/Bootstrap.php#L230) 
 
   - [\Magento\Framework\App\Http](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/App/Http.php) - index.php, pub/index.php
     load config area by front name
@@ -64,19 +64,26 @@ Notes:
 [\Magento\Framework\App\Http::launch](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/App/Http.php#L128)
 1. detect config area by front name
 
-`\Magento\Framework\App\AreaList` - areas from argument di.xml
+```php
+<?php
+$areaCode = $this->_areaList->getCodeByFrontName($this->_request->getFrontName());
+$this->_state->setAreaCode($areaCode);
+$this->_objectManager->configure($this->_configLoader->load($areaCode));
+```
+
+`\Magento\Framework\App\AreaList` - areas from argument di.xml ([AreaList](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/App/AreaList.php))
 
 - frontend = [frontname null, router "standard"] --- *default when nothing matched*
 - adminhtml - [frontNameResolver=..., router "admin"]
-  \Magento\Backend\App\Area\FrontNameResolver::getFrontName(checkhost)
+  [\Magento\Backend\App\Area\FrontNameResolver::getFrontName(checkhost)](https://github.com/magento/magento2/blob/2.2-develop/app/code/Magento/Backend/App/Area/FrontNameResolver.php#L83)
   system config `admin/url/use_custom`, `admin/url/custom`
 - crontab = null
 - webapi_rest = [frontName `/rest`]
 - webapi_soap = [frontname `/soap`]
 
-1. ObjectManagerInterface::configure - selected area code
-1. result = FrontControllerInterface->dispatch
-1. ResultInterface.renderResult into response object
+1. [ObjectManagerInterface->configure()](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/ObjectManager/ObjectManager.php#L82) - selected area code
+1. result = FrontControllerInterface->dispatch()
+1. [ResultInterface->renderResult()](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/Controller/AbstractResult.php#L122) into response object
 1. event `controller_front_send_response_before` (request, response)
 
 
@@ -93,9 +100,9 @@ Notes:
 - *Default* global preference app/etc/di.xml - Magento\Framework\App\FrontController
 - "frontend", "adminhtml", "crontab" area code - no preference, use default *App\FrontController*
 - "webapi_rest (frontName `/rest`) - preference module-webapi/etc/webapi_rest/di.xml - *\Magento\Webapi\Controller\Rest*
-- "webapi_soap" (frontname `/soap`) - preference module-webapi/etc/webapi_rest/di.xml - *\Magento\Webapi\Controller\Soap*
+- "webapi_soap" (frontname `/soap`) - preference module-webapi/etc/webapi_soap/di.xml - *\Magento\Webapi\Controller\Soap*
 
-### [App\FrontController](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/App/FrontController.php):
+### [\Magento\Framework\App\FrontController](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/App/FrontController.php):
 
 - routerList
 - action = router[].match
@@ -111,17 +118,32 @@ Notes:
 
 - [\Magento\Framework\Controller\ResultInterface](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/Controller/ResultInterface.php) - renderResult, setHttpResponseCode, setHeader
 
-  Raw, Json, Forward, Layout, Page, Redirect
+    Implementations:
+    - [Result\Raw](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/Controller/Result/Raw.php) -> Result\AbstractResult
+    - [Result\Json](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/Controller/Result/Json.php) -> Result\AbstractResult
+    - [Result\Forward](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/Controller/Result/Forward.php) -> Result\AbstractResult
+    - [\Magento\Framework\View\Result\Layout](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/View/Result/Layout.php) -> Result\AbstractResult
+    - [\Magento\Framework\View\Result\Page](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/View/Result/Page.php) -> \Magento\Framework\View\Result\Layout
+    - [Result\Redirect](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/Controller/Result/Redirect.php) -> Result\AbstractResult
+
+- [\Magento\Framework\App\ResponseInterface](https://github.com/magento/magento2/blob/2.2-develop/lib/internal//Magento/Framework/App/ResponseInterface.php) - sendResponse
 
-- \Magento\Framework\App\ResponseInterface - sendResponse
-  Console\Response, Response\FileInterface, PhpEnvironment\Response, Webapi\Response, Rest\Response
+    Implementations:
+    - [Console\Response](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/App/Console/Response.php)
+    - [\Magento\MediaStorage\Model\File\Storage\FileInterface](https://github.com/magento/magento2/blob/2.2-develop/app/code/Magento/MediaStorage/Model/File/Storage/Response.php) -> \Magento\Framework\App\Response\Http
+    - [\Magento\Framework\HTTP\PhpEnvironment\Response](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/HTTP/PhpEnvironment/Response.php) -> \Zend\Http\PhpEnvironment\Response
+    - [\Magento\Framework\Webapi\Response](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/Webapi/Response.php) -> \Magento\Framework\HTTP\PhpEnvironment\Response
+    - [\Magento\Framework\Webapi\Rest\Response](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/Webapi/Rest/Response.php) -> \Magento\Framework\Webapi\Response
 
-### [Controller\Rest](https://github.com/magento/magento2/blob/2.2-develop/app/code/Magento/Webapi/Controller/Rest.php):
-- process path [/$store]/... - specific store, [/all]/... - admin store, /... - default store
+### [\Magento\Webapi\Controller\Rest](https://github.com/magento/magento2/blob/2.2-develop/app/code/Magento/Webapi/Controller/Rest.php) -> \Magento\Framework\App\FrontControllerInterface:
+
+- preference for FrontController set in [etc/webapi_rest/di.xml](https://github.com/magento/magento2/blob/2.2-develop/app/code/Magento/Webapi/etc/webapi_rest/di.xml#L32)
+- process path [/$store]/... - specific store, [/all]/... - admin store (0), /... - default store
 - a. process schema request /schema
-- b. or process api request (resolve route, invoike route -> service class with params)
+- b. or process api request (resolve route, invoke route -> service class with params)
+
+### [\Magento\Webapi\Controller\Soap](https://github.com/magento/magento2/blob/2.2-develop/app/code/Magento/Webapi/Controller/Soap.php) -> \Magento\Framework\App\FrontControllerInterface:
 
-### [Controller\Soap](https://github.com/magento/magento2/blob/2.2-develop/app/code/Magento/Webapi/Controller/Soap.php):
 - process path (same as REST)
 - a. generate WSDL ?wsdl
 - b. or generate WSDL service list ?wsdl_list

2. Request Flow Processing/2. Demonstrate ability to process URLs in Magento.md

@@ -87,9 +87,13 @@ Module UrlRewrite:
 
 Product:
 
-- event `catalog_product_save_before`
+- event `catalog_product_save_before` - generate URL key by product name (if url key wasn't provided)
+  * [ProductUrlKeyAutogeneratorObserver](https://github.com/magento/magento2/blob/2.2-develop/app/code/Magento/CatalogUrlRewrite/Observer/ProductUrlKeyAutogeneratorObserver.php)
+  * [\Magento\CatalogUrlRewrite\Model\ProductUrlPathGenerator::getUrlKey](https://github.com/magento/magento2/blob/2.2-develop/app/code/Magento/CatalogUrlRewrite/Model/ProductUrlPathGenerator.php#L125)
+
+- event `catalog_product_save_after` - generate and replace URL rewrites (when changed url_key, categories, websites or visibility)
   * [ProductProcessUrlRewriteSavingObserver](https://github.com/magento/magento2/blob/2.2-develop/app/code/Magento/CatalogUrlRewrite/Observer/ProductProcessUrlRewriteSavingObserver.php)
-  * \Magento\CatalogUrlRewrite\Model\ProductUrlRewriteGenerator::generate
+  * [\Magento\CatalogUrlRewrite\Model\ProductUrlRewriteGenerator::generate](https://github.com/magento/magento2/blob/2.2-develop/app/code/Magento/CatalogUrlRewrite/Model/ProductUrlRewriteGenerator.php#L128)
   * deleteByData, replace
 
 Category:
@@ -102,6 +106,8 @@ Category:
   * child category.url_path
 
 - event `catalog_category_save_after` - when changed (key, anchor, products)
+  * [CategoryProcessUrlRewriteSavingObserver](https://github.com/magento/magento2/blob/2.2-develop/app/code/Magento/CatalogUrlRewrite/Observer/CategoryProcessUrlRewriteSavingObserver.php#L90)
+  * [\Magento\CatalogUrlRewrite\Observer\UrlRewriteHandler::generateProductUrlRewrites](https://github.com/magento/magento2/blob/2.2-develop/app/code//Magento/CatalogUrlRewrite/Observer/UrlRewriteHandler.php#L124)
   * ... lots of logic
 
 

2. Request Flow Processing/3. Demonstrate ability to customize request routing.md

@@ -2,7 +2,7 @@
 
 ## Describe request routing and flow in Magento.
 
-Frontend routers:
+[Frontend routers](https://devdocs.magento.com/guides/v2.2/extension-dev-guide/routing.html):
 
 - robots (10)
 - urlrewrite (20)
@@ -41,13 +41,17 @@ reference route by ID and add own module "before" original module.
 
 ### How do you handle custom 404 pages?
 
-1. If front controller catches NotFoundException, it changes action name *"noroute"* and continues loop.
+1. If [front controller](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/App/FrontController.php#L61-L65) catches [\Magento\Framework\Exception\NotFoundException](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/Exception/NotFoundException.php), it changes action name *"noroute"* and continues loop.
    E.g. catalog/product/view/id/1 throws NotFoundException. catalog/product/noroute is checked.
 
 1. If standard router recognizes front name but can't find controller, it tries to find *"noroute"*
    action from last checked module.
    E.g. catalog/brand/info controller doesn't exist, so catalog/brand/noroute will be checked.
+
+   [\Magento\Framework\App\Router\Base::getNotFoundAction](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/App/Router/Base.php#L237)
 
 1. If all routers didn't match, default controller provides two opportunities:
-  - set default 404 route in admin config `web/default/no_route`
-  - register custom handler in noRouteHandlerList
+  - set default 404 route in admin config `web/default/no_route` (see: [\Magento\Framework\App\Router\NoRouteHandler::process](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/App/Router/NoRouteHandler.php#L34))
+  - register custom handler in [noRouteHandlerList](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/App/Router/NoRouteHandlerList.php):
+    * backend (sortOrder: 10) [Magento\Backend\App\Router\NoRouteHandler](https://github.com/magento/magento2/blob/2.2-develop/app/code/Magento/Backend/App/Router/NoRouteHandler.php#L44) -> `adminhtml/noroute/index`
+    * default (sortOrder: 100) [Magento\Framework\App\Router\NoRouteHandler](https://github.com/magento/magento2/blob/2.2-develop/lib/internal/Magento/Framework/App/Router/NoRouteHandler.php)

2. Request Flow Processing/4. Determine the layout initialization process.md

@@ -10,7 +10,7 @@ View\Layout::*build* = View\Layout\Builder::*build* - once
 
 1. generateLayoutXml - joins `_updates` into XML string, loads XML object, initiailzes `_elements` = []
 
-    * layout.generaXml
+    * layout.generateXml
     * no events
 
 1. generateLayoutBlocks - layout.generateElements
@@ -213,11 +213,11 @@ Only containers
 
 
 ### page result.renderResult:
-- View\Resuls\PageFactory.create
+- View\Result\PageFactory.create
 - View\Result\Page::addDefaultHandle - `default`, `$fullActionName`
 
 - View\Page\Config.publicBuild = build
-- View\Page\Builder.build - extends View\Layout\Builder, custom readPageLayout on step generatelayoutBlocks
+- View\Page\Builder.build - extends View\Layout\Builder, custom readPageLayout on step generateLayoutBlocks
 
     * (inherit) loadLayoutUpdates
     * (inherit) generateLayoutXml

3. Customizing the Magento UI/1. Demonstrate ability to utilize themes and the template structure.md

@@ -244,7 +244,7 @@ All same as layout, but subDir 'page_layout':
     <theme>*_*/page_layout/override/theme/*/*/*.xml
 ```
 
-View\Layout\ProcessorInterface = View\Model\Layout\Merg
+View\Layout\ProcessorInterface = View\Model\Layout\Merge
 - $updates - array of all found string XML file contents E.g.
 ```
   updates[] = '<body><block name="someBlock"...'
@@ -260,8 +260,8 @@ View\Layout\ProcessorInterface = View\Model\Layout\Merg
 - create new theme from scratch without parent when design is very different from existing
 - inherit new theme to add smaller customizations - move, hide, reorder elements, change block arguments, html attributes
 - new theme can be assigned to specific store view, for example for b2b store
-- theme can apply dynamically based on browser user agent as exception - enter regexp
-    Content > Design > Implementation > [Edit] > Design Rule > User Agent Rules
+- theme can apply dynamically based on browser user agent as exception - enter regexp in
+    _Content > Design > Implementation > [Edit] > Design Rule > User Agent Rules_
     Full page cache and design exception:
 ```
     plugin magento-store/etc/di.xml:
@@ -285,9 +285,9 @@ View\Layout\ProcessorInterface = View\Model\Layout\Merg
 
 theme.xml - parent
 
-Determine theme hierarch of existing project:
+Determine theme hierarchy of existing project:
 
-- Go to Content > Design > Configuration
+- Go to _Content > Design > Configuration_
 - Check "Theme Name" column on row with store view under question
 - find paths to all available themes in app/etc/design/frontend/* or vendor/*/theme-* (conventionally)
   or find programmatically: